Despite Media, Parents Unaware of Disneyland Measles Outbreak

Despite wide publicity accorded the 2014 to 2015 national outbreak of measles, linked to Disneyland in Orange County, California, many US parents remained unaware of the spate of cases, according to survey results from parents of children aged 5 years and younger. Furthermore, although media coverage of the outbreak raised parents' vaccine awareness and confidence, for some it also heightened concerns about vaccine safety and efficacy, researchers report in an article published in the February issue of Health Affairs.

"In today's crowded communication and media landscapes, individuals have much flexibility and great freedom in the types of information they view; thus, even major public health events are not guaranteed to reach all audiences, including those most in need of the information," write Michael A. Cacciatore, PhD, an assistant professor in the Department of Advertising and Public Relations at Grady College, University of Georgia, Athens, and coauthors.

Parents who were most aware of the outbreak had the highest levels of confidence in and support for immunization mandates; however, they also expressed concerns about vaccine risks.

Using data from two surveys, one conducted before the outbreak (in November to December 2014), and the other after the outbreak (in May to June 2015), the investigators studied parents' confidence in vaccination and intentions to immunize their children in the future, as well as the effect of the measles outbreak on these views. Both surveys had a final sample size of 1000.

In the postoutbreak survey, 52.6% reported at least some degree of awareness of measles cases in the last 4 months, 33.2% reported no awareness, and 13.7 percent responded “don't know.” The latter were excluded from subsequent analyses.

Postoutbreak respondents were classified as having no (mean n = 332), low (mean n = 279), or high (mean n = 244) awareness of the outbreak, with the most aware group more likely to be white and somewhat older and better educated.

Despite heavy media coverage, only about one in four reported reading, hearing, or seeing a great deal about the outbreak and considering themselves to be highly informed about and attentive to it.

"The overall low levels of awareness about the outbreak initially surprised me," Dr Cacciatore told Medscape Medical News. "However, you can reasonably make the case that more than 50% awareness is quite impressive in our current media environment."

However, the heightened concerns about vaccine safety and efficacy were not particularly unexpected, said Dr Cacciatore. "That some may have encountered information that framed the outbreak as an example of vaccines' failure to prevent an illness doesn't surprise me, especially if people are searching for their information online," he explained.

Between the two polls, the vaccine concerns scale (1 - 10) went from a score of 5.29 overall preoutbreak to postoutbreak scores of 6.12 in the no-awareness group, 4.60 in the low-awareness group, and 5.77 in the high-awareness group.

"This suggests a trend toward growing skepticism about childhood vaccinations and that different groups followed and interpreted the issue differently," said Dr Cacciatore. "We suspect that the low-awareness respondents paid only cursory attention to the outbreak because they are largely a group of strong vaccine proponents. Their need for information is limited because their minds are made up."

In contrast, the high-awareness group appeared to consist of both strong opponents and proponents of vaccines, "groups that became even further entrenched in such attitudes postoutbreak."

There were relatively small differences in parents' vaccine-related intentions pre- and postoutbreak. In the preoutbreak poll, 76.8% planned to have their children receive all vaccinations. Postoutbreak, the most aware parents exhibited more confidence in immunization and more support for vaccination mandates, with 76.2% intending to have their children receive all recommended vaccines compared with 64.9% in those who had no awareness. Among low-awareness parents, the "minds made up" group, the proportion was a bit higher, at 83.5%.

Knowledge of the outbreak had largely positive effects on vaccine attitudes and behaviors, said Dr Cacciatore. "But while the outbreak correlated with overall higher levels of reported confidence and lower levels of reported concern, this pattern was not consistent. We found heightened concerns and even increased intentions to not vaccinate among some parents who closely followed the outbreak."

The outbreak prompted the American Academy of Pediatrics to release updated measles guidelines in February 2015.

This study was funded by the Grady College of Journalism and Mass Communication at the University of Georgia. The authors have disclosed no relevant financial relationships.